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This paper shows the results on the data transmission over distances of up to 350 m SI-POF with KDPOF Media Converter based on Gigabit POF Transceiver KD1001 (KD-EVK1001MC Evaluation Kit) and laser diode (LD) operating at 520 nm. A bit rate of 1 Gbit/s with 16-PAM modulation scheme can be achieved over 200 m SI-POF. At longer distances, the bit rate is automatically reduced by KDPOF transceiver according to the actual channel capacity.
We report on a proposal for an incoherent optical frequency domain reflectometry (I-OFDR) for 1-mm core diameter PMMA SI-POF. An avalanche photodiode receiver and optimized transmitter based on a 515-nm laser diode allow measurement up to 200 m SI-POF. The measurements have been carried out using a vector network analyzer; the subsequent data processing has been implemented in MATLAB.
Scattering Into Guided Modes Due to Imperfect Graded-Index Structure in Polymer Optical Fibers
(2020)
Rayleigh scattering in graded-index polymer optical fibers (GI-POF) is studied under the assumption that spherical scatterers are uniformly distributed within the layers of concentric ring structure. This approximation allows to describe typical imperfections occurring during the fabrication of GI-POFs. For the purpose of experimental characterization by side illumination, an analytical model of the light conversion into waveguide modes has been developed. This model describes the mode excitation by a multiplicative contribution of three different physical mechanisms. The corresponding experimental analysis of the light scattering has been performed and compared with numerical simulation results for the fibers with single-ring and multi-ring structures. Besides the application to GI-POFs, this article can be also applied to multi-step index fibers.
Fiber Bragg grating (FBG) sensor technology is expected to make an important contribution to extending the lifetime of polymer electrolyte membrane (PEM) fuel cells. It allows accurate measurements of in-situ operating temperature and humidity, which is essential for an accurate control of both. For these applications an accurate and reliable calibration is crucial. This paper demonstrates the successful use of a 2x2 factorial calibration method for calibration of two standard FBGs for application in a PEM fuel cell. The calibrated low-cost FBG sensor allows temperature and humidity measurements with a RMS error (RMSE) of 0.45°C and 4.8 %RH, respectively.
Entwicklung und Charakterisierung eines Erbium-dotierten Glasfasersensors zur Temperaturmessung
(2024)
Abstract. A wavelength tuning range up to 12 nm has been achieved
over 12 µs pump current pulses within a usable time of 10 µs applied to VCSELs operating in the near infrared around 1550 nm. The instantaneous optical frequency shift has been measured with an interferometric setup; the overall tuning range has then been verified with an optical spectrum analyzer. The repetition rate of the current pulses can
be as high as 20 kHz with almost no influence on the sweep parameters. These
results can be used for fast spectroscopic gas analysis or for rapid interferometric swept-source distance sensors.
Optical frequency tuning ranges up to 600 GHz or 4.8 nm have been achieved within microseconds and a standard telecom DFB laser diode operating at 1550 nm. The dynamic optical frequency tuning is induced by electrical current pulse injection and measured using an interferometric setup. Potentially, low-cost sensor systems based on optical coherence tomography (OCT) or coherent optical frequency domain reflectometry (c-OFDR) could be realized, achieving sub-mm two-point range resolution or even better single-point range precision within a few microseconds for a single measurement.